Conventionally, a telecommunications satellite comprises a payload equipped with a reception antenna adapted to receive useful signals transmitted by terrestrial transmitters, in order to retransmit them to other terrestrial receivers.
It is not unusual for a telecommunications satellites to receive, in addition to useful signals, one or more spurious signals that disrupt the reception of said useful signals and can lead to a degradation in the services offered by the telecommunications satellite. For example, a spurious signal can correspond to a signal transmitted by an intentional jammer. The spurious signal can also correspond to a signal transmitted by an unintentional interferer, for example, a terrestrial transmitter of a terrestrial telecommunications system using the same frequency bands as the telecommunications satellite, or an incorrectly pointed terrestrial transmitter of a neighboring satellite telecommunications system.
In order to be able to attenuate or suppress a received spurious signal, knowing the position of the transmitter (jammer or interferer) that is the source of this spurious signal can be useful. Once this position is known, it is possible, for example, to intervene on site in order to interrupt the transmission of the spurious signal. However, it is not always possible for the interruption of the transmission of the spurious signal to be forced, particularly in the case of an intentional jammer located in a geographical area in which intervention is not possible.
By way of an alternative or in addition, in the case of a reception antenna with a modifiable radiation pattern (for example, in the case of a reception antenna formed by an array of elementary reception antennas), said radiation pattern can be modified so as to strongly attenuate all the signals received in the direction of arrival of the spurious signal.
However, the performance of such a solution depends on the precision of the estimation of the direction of arrival of the spurious signal. Furthermore, such a solution implies that the useful signals, which are received in substantially the same direction of arrival as the spurious signal, are also strongly attenuated. Finally, in order to be able to attenuate the direction of arrival of the spurious signal in a spatially selective manner, equipment needs to be used that is both expensive and heavy.